α-Diimine transition-metal complexes: Mechanochemistry − A new synthetic approach

•Synthesis of Ni(II) and Co(II) complexes using solvent-free mechanochemistry.•Very short reaction times and quantitative yields.•The same products obtained using starting from NiBr2 instead of [NiBr2(DME)].•α-diimine Co(II) complexes were obtained using CoCl2 as starting material.•XRPD and SCXRD used as main characterisation tools.

Preliminary results on the preparation of nickel(II) and cobalt(II) complexes containing α-diimine ligands using a mechanochemical approach are presented. The solvent-free reaction of [NiBr2(DME)] (DME = 1,2-dimethoxyethane) with the appropriate α-diimine ligand led to the formation of the expected Ni(II) complexes in very short reaction times and with quantitative yields. The same compounds were also successfully synthesised when NiBr2 was employed. This methodology was extended to the preparation of [Co(α-diimine)Cl2] complexes through the reaction of CoCl2 with different α-diimine ligands. These compounds were characterised by XRPD and SCXRD, when possible. The results obtained confirm that mechanochemistry has an enormous potential and that is an effective technique for the synthesis of coordination and organometallic compounds.

Graphical abstractPreliminary results on the synthesis of nickel(II) and cobalt(II) complexes containing α-diimine ligands using a solvent-free mechanochemical approach are presented, showing better yields and shorter reaction times compared to classical solution methods.Figure optionsDownload full-size imageDownload as PowerPoint slide